package main
import ("fmt"
"math")
type geometry interface{
	area() float64
	perim() float64
}

type rect struct{
	width,height float64
}

type circle struct{
	radius float64
}

func (r rect) area() float64{
	return r.width*r.height
}

func (r rect) perim() float64{
	return 2*r.width+2*r.height
}

func (c circle) area() float64{
	return math.Pi*c.radius*c.radius
}

func (c circle) perim() float64{
	return 2*math.Pi*c.radius
}

func measure(g geometry){
	fmt.Println(g)
	fmt.Println(g.area())
	fmt.Println(g.perim())
}

func main(){
	r:=rect{width:3,height:4}
	c:=circle{radius:5}
	measure(r)
	measure(c)
}